Multiparty-line exchange system.



PATENTED JULY 3, 1906.

G. BABGOGK. MULTIPARTY LINE EXCHANGE SYSTEM.

APPLICATION FILED NOV. so. 1903.

Wifnsssas: Invenfur Garrlaunfi human.

AIR mug 1 g w Wi/-J UNITED STATES PATENT OFFICE.

' GARRISON BABCOOK, OF'CHICAGO, ILLINOIS,ASSIGNOR TO STROMBERG- CARLSON TELEPHONE MANUFACTURING COMPANY, OF ROCHESTER,

NEW YORK, A CORPORATION OF NEW'YORK.

MULTlPARTY-LINE EXCHANGE SYSTEM.

Specification Intten Patent.

Patented m a, 1906;

Application filed November 30. 1908. Serial No. 188,114.

a T at whom it may concern:

ence being had to the accompanying draw in s, forming a part of this specification.

y invention relates to multipart -telephone exchan e systems, and has for its object improved and connections whereby the central operator may more readily establish circuit conditions necessary for such systems.

My invention is particularly adaptable'to' .a system-such as described in my Patent No. 763,351, dated June 28, 1904, in which it is necessary for the operator to successively send setting-up current, locking current, signaling-current, and restoring-current into the, line to properly adjust or rearrange sub- 2 scribers substation apparatus, whereby to selectively signal and connect subscribers together for conversation and to restore the system to its normal condition after conclusion of the conversation. In such systems heretofore it has been necessary for the operator to connect the cord apparatus with one plug of the cord-circuit to set up the necessary circuits at the substations connected with the calling-line and then to connect the central apparatus with theother plug of the cord-circuit to set up the necessary circuit conditions at the substations connected with the called liiie. This operation occasioned great loss of time, and the featuresof my present invention are embodied in an im roved operator"s cord-circuit which enables t e central apparatus to be associated with both plugs of the cord-circuit at the same time,- whereb the necessa both tii e calling an called lines may be simultaneously established, thus reducing the time consumed to a minimum.

I also provide improved means for automatically connecting the desired substations into telephonic communication with the line and automatically'eiicluding all other substations from the line. employ a contact which is caused to travel central-exchange apparatus circuit conditions on- For this purpose I.

under a plurality of contactbuttons arra%ged in staggered arrangement, as-shown in igure 2, one he of buttons being associated with the front plug and the other line being associated with'the rear plug, each buttoncories onding to one of the substations connected with the line'with which the corresponding plug is associated. If connection is desired between two substations and the rear and front lugs being associated respectively, with t e calling and-called lines,

e button corresponding in number to the calling subscriber is depressed and the .but-. ton corresponding in number to the called subscriber is alsodepressed and brought into the path of the traveling contact.

Switching mechanism for associating pul-i sating current with the lines is adapted tobe actuated in harmony with thetraveling contact, and this ulsating current serves to step -forward swi-tc -arr'ns at the substa'tions, and when the switch-arms are in a.certain position the traveling contact at the central excha e will be in contact with the correspon in depressed buttons and a circuit will be estab islied through additional substation apparatus,- whereby the desiredsubscribers are .telephonically connected with the line and all other subscribers are locked out.

' In Fig. 1 I have di rammatically shown a multiparty-linetialep one system and my improved cord-circuit associated therewith, Fig. 2 showingthe. arrangement of the buttons associated with a cord-circuit.

At each substation there is a polarized electrom'agnet 1, whose armature is provided with an arm 2, terminating in pawl mechanism 3. A ratchet-wheel 4, mounted upon a shaft 5, is eng ed by said pawl mechanism to step forwar a switch-arm 6, secured to the shaft. over a ring 7, equally-s aced oles 8, into any one of w 'ch may be aced a contact-pin .9, adapted to be engage by the arm 6 upon its rotation about the-ring h 7. The contact 10 is disposed above t e contact A relay 11 is connected in circuit between the contact-pin 9 and the earth' mpg, but insulated therefrom, and the arm 6 is normally in engagement with said The end of said arm 6 travels provided with a pluralit of the armature is attracted tov close contact,

with the contact-spring 14, and a detent le ver serves to maintain contact between the switch-armsllS and spring 14. A receiver 16 normally rests on the switch hook 17, which engages the switch-springs 18 to normally include the signal-bells 19 in circuit. A local transmitter-circuit 20 is also associated with the switch-springs 18, and by means of a calling-generator 21 the subscriber may signal the central exchange.

At the central exchange I have shown a cord-circuit provided with a rear plug and a front plug 23, the rear plug engaging the spring-jack connected with the line to which is connected the calling subscriber Grand the front plu being inserted in the spring-jaclz connecte with the line to which is connected the called subscriber C The selective keys 24 and 24, release-keys 25 and 25, selective ringing-keys 26 and 26, and metallic ringling-keys 27 and 27 are respectively associated with the rear plug and the front plug of the cord -'circuit. Circuit-changing switch mechanism 28 is associated with the rear plug, and circuit-changing-mechanisrn 28 is associated with the front plug. The circuitchanging mechanism 28 consists of anachrating-spring 29, adapted to alternately engages rin s and 31, and a spring 32'is connectec with but insulated from the switch 29 and alternately makes and breaks contact with a switch-spring 33. The circuit-changing mechanim 28" consists of a spring 29,

tact with the spring 35.

adapted alternately to engage springs 30 and 31, and an actuating-spring 32is rigidly secured to but insulated from the spring 29 and alternately makes and breaks con- A cam 34 of insulating material revolves between the actuating-springs 2-9 and 32, whereby the circuit changing mechanisms are actuated to alternately 'shortcircuit the lines connected therewith and to connect with said lines source of current 35, whereby current iinpulses are sent through the substation electro the front plug, while buttons 2" 1* r, &c., in

the rear row are associated with the rear plug, there being sufficient buttons m each row to provide for any number of substations on a hue, each substation being represented by a button. Below these buttons 1 dispose an endless conductor, which may be in the shape .to be C, connectedwith line Y.

of a band 36, adapted to travel over carrierwheels 37 and 38. The wheel 38 may be driven by weight mechanism 39, as shown, or may be actuated byspring or other means, while the carrier-wheel 37 is in driving rela tion witli the cam 34. Equally-spaced contact-ridges 40 project from the band 36 and serve to engage and to restore the keys which have been depressed. The band 36 is continually connected with the negative side of the battery 35 through a conductor ll and a wiper-contact 42, while the buttons f &c., and r, &c., are continually in connection with the earth through a conductor 41 and contact-springs 42.

The operation of the system is asfollows: Suppose the calling subscriber to be C, connected with line X, and the called subscriber Normally the switch-arms 6 are in engagement with their contacts 10, and the receivers are on the hook. The subscriber by actuation of the calling-generator 21 may actuate the indicatcr-signal 45 at the cehtral exchange, in reply to which signal the operator inserts one of the plugs into the jack connecting the line X, the plug'in the illustration being the rear plug. After central ascertains the desired substation, which inthis case is en posed to be C she inserts the other plug in t 1e springjack connectingwith the telephone-line Y. She now actuates the selective keys 2e and- 24 and depresses actuating-buttons f corresponding with substation C and actuating-button r g'corresponding with substation C One of the contact-ridges a0 is disposed at the left of the actuating-buttons just in rent of the button f. The starting-key 43 has been pulled upwardly, as shown, to re lease the contact-ridge 40 to allow the weight mechanism to revolve the band 36, at the same time revolving cam 34, the cam in the figure being shown as just depressing the ac tuating-spring 32, and when. said actuatin spring and the associated spring 29 are fully depressed to the right and the actuatingspring 29 and the associated spring 32 are entirely retracted toward the right the contact- I ridge 40 will be directly below the actuatingbutton f, and the. circuit-changing mechanroe ism 28 serves to short-circuit the line X- through the following circuit: actuating-' spring 29, conductor 46, through the selective key 2 1 to the tip .of the rear plug, thence through the substations on the line, back to the sleeve of the rear plug, to the selective key 24, to conductor 47, and to spring 31, any static charge on the line being thus removed. The circuit-changing mechanism 28, however, sends a positive'impulse' through the substations on line Y through the following circuit: actuating-sp i ing 32, conductor 48,

selective key 24", conductor 49, to the sleeve of the frent plug 23, through the substation apparatus on line C back to the tip ol the front plug to conductor 50, through the selective key 24, conductor 51, spring 29, spring 30, conductor 41, to the battery 35, conductor 52, conductor 53, and spring 33. This current impulse is in a direction to actuate the electroma 'nets 1 at each of the substations on line and the switch-arm 6 at the substations will be stepped forward to be disposed over the first hole in the ring 7. When the ridge 40 has passed to a position below the actuating-button r, the cam 34' will have rotated one-half revolution to the position shown in dotted lines, and the switch mechanism will be in the dotted position, as shown. Switch mechanism 28 now closes the following circuit: from the positive side of the battery 35 to conductor 52, to spring 33, spring 32, conductor 47, selective key 24, sleeve of the rear plug, through the electromagnets 1 on line X, back to the ti of the rear plug, through the selective ey 24, through the conductor 46, spring 29, spring 30, conductor 54, conductor 55, and back to the negative side of the battery. The electroinagnets on line X will be actuated to step the switch-arm '6 forwardly to be disposed over the 'fir'st hole, as shown at substation C The switch mechanism 28, however, short-circuits the line Y through the following circuit: spring 29, sprin 31, conductor 48, selective'key 24', con uctor 49, the sleeve of the front plug; through the line Y, back to the tip of t e ont plug, to con ductor 50, through the selective key 24, to conductor 51, and back to spring 29. Any static charge on. line Y. is thus removed. When the contact-ridge 40 assumes a position below-the de ressed button f as shown in dotted lines, tlib cap 34 will have rotated a complete revolution back to the full position and line X is again short-circuited, while another impulse is sent from the battery through the switching mechanism 28 into line to actuate electromagnets 1 to step the switch-arms 6 to be disposed over the second hole. However, at the called substation C a contact-pin 9 is inserted in the second hole, and after this second actuation of the electromagnets 1 the switch-arms 6 at substation C is in contact with the pin 9. Alsoat the same time the contact-ridge 40 is in contact with the depressed button f 2 at the central exchange and'the following circuit established: from the negative side of the battery 35 to conductor 41,-wiper-contact 42, contact-band 36, contact-ridge 40, actuatingbutton f spring 42, conductor 41, to the ground and thence through the ground conduct-or 56 at the substation C throu h the relay 11, through conductor 57, to t e pin 9, through the arm 6, through conductor 58, to conductor 59, to conductor 60 of the line Y, to the sleeveof the front plug, to the conductor 49, through the selective key 24, conductor 48, actuating-spring 32, spring substation C the relay 11 receiver at the substation C which a contact-pin 9 is inserted in the second hole, and as the arms 6 at all the other substations are moved away from their normal contact 10 circuit through the receivers 16 at all the substations will be broken and the subscribers locked out. However, as at has been energized to close contact between the switch-lever 13 and contact 14, the receiver 16 at this substation will be connected with the line through the contact 14, switch-arm 13, and detent 15 instead of being normally connected with the line through the contact 10 and switch-arm 6. When the contact-ridge 40 is in contact with the depressed actuatingbutton T the switching mechanisms 28 and so it 28' will have been actuated to bring all the switch-arms 6 into position over the third hole, and the following circuit will be established through therelay 11 at the substation C from the negative side of the battery 35, conductor 41, contact 42, contact-band 36, contact-ridge 40, actuating-button 1' spring 42, conductor 41, ground G, thence to the ground conductor 56 at substation C tact-pin 9, switch-arm 6, conductor 58, conductor 59, to conductor 60 of the line X, to

relay 11, con- Y the sleeve of the rear plug, through the selective key 24, to conductor 47, to spring 32,

spring 33, and conductor52 back to the ositive side of the battery. Relay 11 atvsu station C will now become energized to close contact between the switch-lever 13 and contact 14, and the detent 1.5 will drop to maintain this connect-ion, relay 11 being the onl T one connected with line X, which is energized, as at no other of the substations is there a contact-pin in hole No. '3, and, as in line Y, all the other substations will be disconnected and locked from the connected with the line. by virtue of the switch-lever 13, contact 14, and detent-lever 15. The arms 6 are stepped around to pass beyond the entire number of holes corresponding with the number of subscribers connected with the line, and when the arms have thus reached the end of their rotation the contact-'- ridge 40' will be engaged by the starting-button- 43, and the actuating-cam 34 will remain stationary. Having thus connectedthe desired subscribers to the telephone-line and excluded all others, the central operator re-- leases the selective keys 24 and 24 and actuates the rin in -key 26 to send a ringing-current throug the following circuit: from the ,circuit, the however, being ringing-generator 63 to conductor 64,through spring 65, spring 66, conductor 67 to ground, thence to the groundconductor 56 at the substation through the signal-bell 19, through the spring 68, spring 69, to conductor 70, switch-lever 13, contact 14, detent 15,

' conductor 59, conductor-60, to the sleeve'of the front plug, to conductor 49, through selective key 24, which is now closed, to conductor 71, through the release-vkey 25, to conductor 72 and through the actuated ringing-key 26 to conductor 73, back to the generator 63. The called subscriber (1 upon receiving the signal removes the receiver from the hook, and subscribers C and C are plug, through the electromagnets 1, con-.

nected with the line X, to the'sleeve of the rear plug, through the selective key 24, conductor 75, through the actuated release-key 25 and back to the negative side of the battery. The direction of this current is opposite to thesetting-up current sent into the line by the switching mechanism 28 and 28,

and consequently the polarized electromagnets 1 are energized to withdraw the pawl allow springs 76to return the switch-arms 6 to their normal contacts 10. 'In the same manner an actuation of release-key 25" will send a current into the line Y to energize electromagnets 1 to release the switch-arms 6 on said line. At each substation there is also provided a cam-arm 77, adapted to engage the cam-surface 78 at the rear of 'thedetent lever 15, and as said cam-arms are rotated backward upon release by the elect-romagnets this cam-surface is engaged, whereby the detent levers at substation C C are raised but of latching engagement with the switchlevers 13, whereby contact between said switch-levers and contacts 14 is broken. Thus upon simultaneous action of keys 25 mechanism 3 from the ratchet-wheels 4 to and 2. all the substation apparatus is simultaneously brought to the normal condition, and

central may withdraw the plugs from'the jacks.

I also provide ringing-keys 27 27, which.

enables the operator to connect a substation, such as shown, with a foreign telephone-cu cuit in which the signal-bells at the substations are connected in'bridge of the metallic limbs of the line. If either the called or calling substation be one at which the signal is connected in bridge of the metallic limbs, the

central operator actuates either of the metallic ringing-keys '27 or 27, and thus may signal said substation, it being in this case necessary to actuate only the selective keys and the release-keys connected with the plug which is in association with the multiparty-line.

I thus provide a cord-circuit by means of which it is possible for the operator to estal-- the necessary signals at the calling and called substations at the same time, thus reducing the time consumed to a minimum. The apparatus which I associate with the cord-cincuit is also entirely automatic, the mere actuation ofan actuating-button serving to set the apparatus in motion and to check it at the proper instant, all the parts of the apparatus cooperating to produce certain results at the proper instant: I

As many modifications may be made without departing from the s irit of the invention, I do not wish to be limited to the exact arrangement as shown; but,

Having described my. invention, I wish-to secure by Letters Patent the following claims:

1. In a telephoneexchange system, the combination with a central exchange, of telephone-lines, leading therefrom, substations connected. with each telephone-line, a cordcircuit at the central exchange, a front and a rear plug for said cord-circuit, a make-and,- break switching mechanism associated with each plug, a source-of current, and means for alternately actuating said switching mechanisms to repeatedly connect each plug, first with said source, then to cause short-circuiting thereof.

2. In a telephone system, the combination with a central exchange, of telephone-lines leading therefrom, a plurality of substations connected with each line, an operators cordcircuit at the central exchange, a front and a re ar plug for said cord-"circuit, a source of ouras, a

nately actuating said switching mechanisms. to repeatedly connect each plug, first with said source and then to cause short-circuiting thereof. 1

3. In a t'elephonaexchange system, the combination with a central exchange, of telephone-lines leading therefrom, a plurality of substations connected with ,cach line, an operator's cord-circuit at the central exchange, a front and rear plug for said cord-circuit, a source of current, keys for connecting said source of current with said plugs, circuit changing switching mechanism connected with said source of current and said keys, and means for actuating said switching mechanism toalternately interrupt the currentflow from said'battery whereby current pulsations are sent through both plugs into the lines connected therewith, and to alternately lish necessary circuit conditions and to give rent, keys in said cord-circuit for connecting source of current, a common meansfor alterplugs, independent short-circuit the plug-conductors whereby the lines connected to tially simultaneously short circuited, substantially as described.

4. In a telephone-exchange system, the combination with a central exchange, of tele phone-lines leading therefrom, substations connected with each telephone-line, an opera tors cord-circuit, a front and rear plug for said cord-circuit, a source of current, independent switching mechanism for each plug connected with said plugs and said source of current, and, means for automatically actuating said switching mechanisms. to repeatedly interrupt the current-flow to send pulsating currents through both plugs and into the telephone-lines connected therewith, and to short-circuit the cord conductors when the flow thercthrough is interrupted, substantially as described.

5. In a telephone-exchange system, the combination with a central'exchange, of telephone-lines extending connected with each line, an operators cordcircuit, a front and rear plug for said cordcircuit, a source of current, an independent key in said cord-circuit for each plug for connecting. said source of current with said switching mechanism for each plug interposed between said source of current and said keys, and means for actuat ing said switching mechanisms to repeatedly interrupt the current-flow whereby current pulsations may be alternately sent through both plugs and into the lines connected therewith, substantially as described.

6; In a telephone-exchange system, the

combination with a central exchange, of telephone-lines extendin therefrom, substations connected with each line, an operators cordcircuit, a front and rear plug for said cord-circuit, a source of current, an independent key in said cord-circuit for each plug for connecting said source of current with said plugs, independent switching mechanism for each plug interposed between said source of ourant and said keys, means for actuatin said switchingmechanisms to alternately nterrupt the current-flow whereby current pulsations may be alternately sent through both plugs and into the lines connected therewith, and to alternately short-circuit the cord conductors whereby the telephone-lines connected with said plugs are alternately short-circuited'to relieve them from static charges,- substantially as described.

7. In a telephone-exchange system, the combination with a central exchange, of telephone-lines extendinn therefrom, substations connected with each e, an operators cordcircuit, a front and rear plug for said cord-circuit, a source of current, an independent key in said cord-circuit for each plug for connecting said source ofcurrent with said plugs, in-

dependent switching mechanism for each said plugs are-substantherefrom, substations plug interposed between said source of current and said keys, means for actuatin said switching mechanisms to repeatedly interrupt the current+flow whereby current pulsations maybe alternately sent through both plugs and into the lines connected therewith, and an independent releasing-key for each. plu whereby said source of current may be bri ged across the cord conductors to send through said -plugs and the lines connected therewith a current-flow in opposite direction to that of the pulsating current-flow, substantially as described. I t

8. In a telephone-exchange system, the combination with a central exchange, of telephone-lines extendin therefrom, substations connected with each e, an operators cordcircuit, a front and rear plug for said cord-circuit, a source of current, an independent key in said cord-circuit for each plug for connecting said source of current with said plugs, independent switching mechanism for each plug interposed between-said source of current and said keys, means for actuatin said switching mechanisms to repeatedly interrupt the current-flow whereby current pulsations may be alternately sent through both plugs and intothe lines connected therewith, a .source,of signaling-current, and an independent ringing-key for each plu whereby signaling-current may be sent su stantially simultaneously through both telephone-lines connected with said plugs, substantially as described.

9. In a telephone exchange system, the combination with a central exchange, of teleconnected with each ine,,an operators cordcircuit, a front and rear plug for said cord-circuit, a source of current, an independent key in said cord-circuit for each lug for connecting said source of current with said plugs, independent switching mechanism for each plug interposed between said source of current and said keys, means for actuating said switching mechanisms to alternately interphone-lines extendin therefrom, substations rupt the current-flow whereby current pulsa- ,tions may be alternately sent through both plugs and into-the lines connected therewith and to alternately short-circuit the cord conductors whereby the telephone-lines connect,- ed with said plugs are alternately short-circuited to relieve them from static charges, a generator source of signaling-current, and an independent key for each p ug whereby signaling-cm'rent may be substantially sent simultaneousl through both telephone-lines connected wit said plugs, substantially as described. v

10. In a telephone system, the combination with a central exchange, of telephonelines leading therefi'om,substations connected with each telephone-line, an operators cord-circuit, front and rear plugs for connect ing said cord-circuit said telephone-line,

a source of current, switching mechanism, means for actuating said switching mechanism for repeatedly interrupting said current flow whereby ulsating-current is sent alternately through oth plugs into the lines toact-uate apparatus connected therewith, and me ans for grounding one side of said source of current after predetermined numbers of pulsations of said current, substantially as described.

11. In a telephone-exchange system, the f interrupt. the current-flow from said source whereby ulsating-current is alternately sent through 0th of'said plugs and into the line connected therewith to' actuate substation apparatus, and means upon predetermined numbers'of pulsations 01 said pulsatin -current whereby one side of said source 0 current is grounded to simultaneously actuate additional apparatusjat the substations connected with said plugs, substantially as described. v

i 12. In a telephone -exchange system, the combination with a central exchange, of telephone-lines leading therefrom, substations provided with substation apparatus connected with each line, an operators cord-circuit, a front and rear plug for connecting said cordcircuit with said lines, a source of current, independent switching mechanism for each plug, and actuating means for said switching 4,0 mechanisms, one position of said actuating means causing one of said switching means to short-circuit its associated plug and causing the other switching mechanism to connect said source of current with said other plug,

said actuating means in its alternate position causing the aforesaid switching mechanism' to connect said source of current with said aforesaid plug and causing said other switching mechanism to short-circuit said other plug, substantially as described.

13. In a telephone-exchange system, the

combination with a central exchange, of telephone-lines leading tl1erefrom,- substations connected with each telephone-line and provided with substation apparatus, an oper-.

ators cord-circuit, front and rear plugs for connecting said cord-circuit with said telephone-lines, a source of current, an independent selective-key for each of said plugs for connecting said source of current therewith, independent switching mechanism interposed between said source of current and each plug, means for alternately actuating said switching mechanism, each switching mechanism in one position causing said plug and the associated telephone-line to be shortcircuited and in its alternative osition caussaid source of current to e connected with .saidpllig and with the line to actuate substation apparatus, a traveling contact continually connected with one side of said source of current, and associate grounded contacts adapted to be interposed in the path of said traveling contact whereby after .predetermined numbers of current pulsations sent intothe lines by means of said switch- 7 ing mechanisms, said traveling contact engages said interposed associate contacts to connect said source of current to the ground whereby additional substation apparatus also connected to ground, is substantially simultaneously actuated.

14. Ina telephone-exchange system, the combination with a central exchange, of telephone-lines leading therefrom, substations connected with each telephone-line and. provided with substation apparatus, an operators cord-circuit, a front'and rear plug for connecting said cord-circuit with said telephone-lines, a source of current, an independent selective key for each plug for associating said source of current therewith and with the line connected thereto, switching mechanism interposed between saidsource of current and said selective keys, means for actuating said switching mechanism whereby current impulses from said source are alternately sent through the front and rear plugs and into the lines connected therewith, and

means at predetermined im ulses for ground ing one side of said source 0 current whereby additional grounded apparatus at the substations is actuated, substantially as described.

15. In a telephone-exchange system, the combination with a central" exchange, of telephone-lines leadin therefrom, substations connected with each telephone-line and provided with substation apparatus, an operators cord-circuit, a front and rear plug for connecting said cord-circuit with said telephone-lines, a source of current, an in dependent selective-key for each plug for associating said source of current therewith and with the line'connected thereto, switching mechanism interposed between saidsource of current and said selective keys, means for actuating said switching mechanism whereby current impulses from said source are alternately sent through the front and rear plugs into the lines connected therewith, a plurality of grounded contact-buttons, each button correspondinglto a substation connected to the lines associated with said plugs, a traveling contact connected with one side of said source, said buttons being adapted to be moved into the path of said. traveling contact and meansfor causing said traveling contact and said switclung-mechanism-actuating means to move in unison whereby at predetermined current pulsations sent into the line said traveling contact is caused to engage the corresponding depressed button grounded apparatus at the vided with Substation apparatus, an operators cord-circuit provided with a front and rear plug)v an independent selective keyfor each plug, a source of current, switching mechanisminter osed between said source of current and said. selective keys, actuating means for actuating'said switching mechan- "whereby said source of current is grounded ism whereby current pulsations are sent' from said source. of current alternately through said selective keys into said lugs and through the lines connected therewith to actuate substation apparatus, a traveling contact connected with one side ofsaid source of current, grounded actuating -buttons adapted, to bedepressed to be engaged by said traveling contact, said buttons corresponding in position to the numbers of substationsconnected with the lines associated with said plugs, detent means forpreventing motion of said traveling contact,- and means upon release of said detent for causing said traveling contact and said svv itching mechanism-actuating means to move in unison whereby at certain predetermined current impulses the depressed buttons are engaged by the" traveling contact to connect said source of current with the-ground whereby grounded pparatus at the calling and called su stations is actuated, substantially as de- 4 scribed.

17 In a telephone-exchange system, the combination with 'a central exchange, of telephone-lines leading therefrom, a plurality of substations connected with each line and provided with substation apparatus, an operators cord-circuit provided with a front and rear plug, an independent selective key for each plug, a source of. current, switching mechanism interposed between said source of current and said selective keys, actuating means for actuatingsaid switching mechanism whereby the current pulsations are sent from said source of current alternately through said selective keys into said plugs and through the lines connected therewith to actuate substation apparatus, a traveling contact connected with one side of said source of current,'grounded actuating-but tons adapted to be depressed to be engaged by said traveling contact, the buttons corresponding in position to the numbers of substations connected withthedines associated with said plugs, detent means for preventing motion of said traveling-contact, means upon ing contact and said-switching-mechanism actuating means to move in unison whereby at certain predetermined current impulses the dQPIESSGCl'bUttOIlS are engaged by the traveling contact toconnect said source of current with the .ground whereby grounded apparatus at the calling, and called substations-is actuated, an independent-selective ringing-key in said cord-circuit for each plug, an actuation of either of said ringing-keys connecting said generator with the associated. plug and a line to actuate signal-receiving apparatus at the substation after actuation of said grounded substation apparatus, substantially as described.

18. In a telephone-exchange system, the

combination with a central exchange, of telephonelines leading therefrom, a plurality of substations connected with'each line and provided with substation apparatus, an op eratorsj cord-circuit provided with. a front and rear plug, an independent selective key for each plug, a source of current, switching mechanism interposed between said source of current and said selective keys, actuating means for actuating said switching mccham ism whereby the current pulsations are sent from said source of current alternately through said selective keys into said plugs and through the lines connected therewith to actuate substation apparatus, a traveling contact connected with one side of said source of current, grounded actuating-buttons adapted to be depressed to be engaged by.said traveling contact, the buttons corresponding in position to the numbers of substations connected with the lines associated with said plugs, detent means for preventing actuating means to move in unison whereby at certain predetermined current impulses the depressed buttons are engaged by the traveling contact to connect said source of current with the ground whereby grounded apparatus at the calling and called substations is actuated, an independent selective ringing-key in said cord-circuit for each plug, an actuation of either of said ringing-keys connecting said generator with the associated plug and a line to actuate signal-receiving apparatus at the substation after actuation of said grounded substation apparatus, and an independent releasing-key for each plug for sending a current impulse of oppositepolarity to the aforesaid current impulscswhcreby actuated substation apparatus maybe released and restored to its normal position, substantially as described.

19. In a telephone system, the combination with a central exchange, of telephonelincs leading therefrom, substations connected with each telephone-line, and provided,

release of said detent for causing said travelwith metallic and grounded substation appa- 13o Iatus, an operators cord-circuit provided with front and rear plugs, a source of current, make-and-break mechanism for each plug for causing pulsating current, an independent selective key for each plug for leading said pulsating current into the associated plug, and a line to actuate the metallic ally-connected substation apparatus, means for grounding said source'of current at certain predetermined pulsations whereby the grounded substation apparatus is actuated, an independent ringing-key for each plug, a generator associated with said'keys, actuation of either of said ringing-keys causing current from said generator to pass through the associated plug, and a line to actuate signaling apparatus at the substations at which the grounded apparatus has been actuated, and an independent releasingdiey for each plug for connecting said source of current with the telephone-lines to' cause a current to flow therethrough in an opposite direction to the aforesaid pulsating-current flow whereby the metallically-connected apparatus is cause to release the substation apparatus, substantially as described.

20. In a telephone-exchange system, the combination with a central exchange, of telepl'ione-lines leading therefrom, substations connected with each telephone-line, a cordcircuit at the central exchange, a front and a rear plug for said cord-circuit, circuit-changing mechanism associated with said cord-circurt, a source of current, and means for actuating said circuits-hanging mechanism to interrup' the current-flow from said source, whereby current pulsations are sent through both of said plugs and to the lines associated therewith to actuate substation apparatus and to alternately short-circuit the cord conductors, whereby the telephrme-lines are short-circuited to release them from static charges, substantially as described.

in a telephone-exchange system, the combination with a central exchange, of telephone-lines leading therefrom, substations connected with each telephone-line, apparatus at each substation adapted for. connec tion with the line conductors and with a third conductor, a cord-circuit at the central exchange provided with a front and rear plug, circuit-changing switch mechanism associated with said cord-circuit, a source of current, means for actuating said circuitchangmg mechanism for lnterruptnig the current-flow from said source, whereby cur-! rent pulsations are sentthrough both of said plugs to actuate substation apparatus connected with the line conductors, and means after predetermined numbers of current pulsations for connecting said source of current with the third. conductor, whereby the apparatus at the substation connected with the third conductor is actuated, substantially as described.

22. In a telephone-exchange system, the combination with a central exchange, of telephone lines leading therefrom connected 'irh substations, apparatus at said substations adapted for connection with the line conductors and with a third conductor, a cord-circuit at the central exchange provided with a front and a rear plug, circuit-changing mechanism associated with said cord-circuit, a source of current, means for actuating said circuit-changing mechanism for inter-- rupting the current-flow from said. source, whereby current pulsations are sent through both of said plugs and into the lines associated therewith to actuate substation apparatus connected with the line conductors, automatic means at the central exchange for connecting said source of current with the third conduci'ior after predetermined numbers of current pulsations, whereby the substation apparatus connected with the third conductor is actuated, a signal at each substation connected with the line 'upon .actua-' tion of the associated apparatus connected with the third conductor, and means the exchange for sending signaling-current simultaneously through the signals connected with the lines by the associated apparatus connected with the third conductor, substantially as described.

23. In a telephone-exchange system, the combination with a central exchange, of tele phone-lines leading therefrom and connected with substations, a signal at the substations, a cord-circuit at the central exchange provided with a front and a rear plug, circuitclmnging mechanism associated;- with said cord-circuit, a source of current, means for actuating said circuit-changing mechanism for repeatedly interrupting the current-flow from said source, whereby current pulsations are alternately sent through both of said plugs and into the lines associated therewith to actuate substation apparatus, and means for automatically connecting said source of current in circuit with said substa tion signal upon predetermined mnnbers of current pulsations, substantially as described.

24. In a telephone-exchange system, the combination with a central exchange, of telephonedines leading therefrom, a substation connected with each telephone-line, a cordcircuit at the central exchange provided with a front and a rear plug, circuit-changing mechanism associated with said cord-circuit, a source of current, means for actuating said circuit-changing mechanism for causing current pulsations to flow alternately through both of said plugs and into the lines to actuate one substation apparatus, and automatic means at the central exchange for causing actuation of other substation apparatusonl upon predetermined numbers of current pu sations sent into the line, substantially as described.

. 25.; In a, telephoneeexchange 'system,,.the

combination with acentral exchange, oftele-- phonelines leading: therefrom, substations connected, with each:itelephoneeline, a cord-a circuit at theexchange provided with a front anda rear plug, circuitechanging mechanism associated with ,saidacOrd-circuit; a source; not current, means for actuating said circuitchanging mechanism for repeatedly interrupting the current-flow from said source, whereby current pulsations are sent through both of said plugs and through the metallic limbs of the lines associated therewith to actuate one substation apparatus, and autom atic means at the central exchange forsending a single impulse from said source to actuate grounded substation apparatus upon predetermined numbers of current impulses sent through the limbs of the lines, substantially as described.

26. In a telephone-exchange system, the combination with a central exchange, of telephone-lines leading therefrom, substations connected with each telephone-line, a cordcircuit provided with a front and a rear plug,

a source of current, circuit-changing mechanism, actuating means tor said circuit-changmg mechanism, means for simultaneously connecting said circuit-changing mechanism,

with both plugs, whereby current impulses are sent into the nnes connected with said plugs, a traveling contact moving in unison with said actuating means, a contact for each substation connected with the plugs disposed in order and adapted to be interposed in the path of said traveling contact, and means for moving said traveling contact and said actuating means, whereby substation apparatus is actuated only upon predetermined numbers of current pulsations through said plugs into the lines connected therewith, substantially as described.

27. In a telephone-exchange system, the combination with a central exchange, of telephone-lines leading therefrom, substations connected with said telephone-lines, an operators cord-circuit provided with a front and a rear plug, circuit-changing mechanism and a source of current connected with said cordcircuit, switch-keys in said cord-circuit for connecting said switching mechanism simultaneously with both plugs, whereby current pulsations are sent through both plugs and into the lines coimected therewith to actuate substation apparatus connected with the line-limbs, grounded apparatus at the substations, and automatic means at the central exchange for connecting said source of current with ground only upon predetermined numbers of current impulses, whereby said grounded substation apparatus is actuated, substantially as described.

28. In a telephone-exchange system, the combination with a central exchange, of telephone-lines leading therefrom, a plurality of vided with apparatus connected to-the limbs of the line and with grounded"apparatus, a

cord-circuit provided with a front and'a'rcar plug, a source of current, circuit-changing mechanism connected with'said source, keys mechanism, whereby current impulses are sent into the associated lines to actuate the substation apparatus connected therewith, means at the exchange for automatically grounding said source of current only at pre-' determined numbers of current pulsations, whereby the substation apparatus is thereupoir connected with said source of current and actuated thereby, a signal at each substation connected in circuit upon actuation of said grounded apparatus, ringing-keys in said cord-circuit for sending ringing-current through both plugs to simultaneously actuate all the signals connected in circuit by said grounded apparatus, and keys in said cordcircuit for sending a current of opposite polarity thrdugh both plugs to simultaneously restore allthe substation apparatus to its normal condition after actuation thereof, substantially as described.

29. The combination with a series of partylines each having a series of stations thereon, of a series of numbered levers or-keys each representing a diflerent station on a line, an impulse sending device, means by which upon moving two of said levers from their normal positions the impulse-sending device will be set for the selection of stations having numbers corresponding to the numbers on in the cord-circuit for connecting'both plugs 1 simultaneously with said circuit-changlng" the moved levers, and means by which upon operating said impulse sending device it will automatically select the desired stations one from each of two lines.

30. The combination with a series of party lines each provided with a series of local stations, and an impulse sending device, of means by which said impulse-sending device may be set for the connection of two stations located on different lines, and means whereby upon operating said impulse-sending device the local stations for which said device has been previously set will be placed in telephonic connection with each other.

31. The combination with two party-lines each having a series of local stations thereon, and means for sending impulses alternately over the two lines, of means for sending an extra impulse over each line, and means by which the impulse-sending devices maybe set so that the extra impulse for each line will IIO come at any desired point within the series of impulses for that line.

, 32 The combination with a station-calling device, means by which it may be set for the selection of any two desired stations, and means for starting it into operation when so set, of means by which said device may oper- Lam simultaneously on two lines whereby a desired station on one. line is placed in telepilcnic connection with a desired station on a different line.

The combination with a station-selecti: (r device, and means for setting it for the selecting of any two stations out of a plurality of stations, of a plurality of party-lines each having a plurality of stat-ions thereon, means by which two such lines may be simultaneonsly connected to said device, and means by which said selecting device will operate simultaneously over both ofthe connected lines and automatically select desired sta- 15 tions thereon 34. The combination with aseri'es of partylines, each having a lurality of stations thereon, of a station-seliecting device, means for connecting two of said lines to said device, and means by \vhichvupon operating said de- 20 vice a desired station on one of said lines will be automatically placed in telephonic coni ection with a desired station on the other In witness whereof I hereunto subscribe 25 my name this 16th day of November, A. D. 1903.

GARRISON BABCOCK.

Witnesses:

CHARLES J. SCHMIDT, LEONARD W. NOVANDER. 

